Architecting security solutions for today's diverse computer systems is a challenge. The modern business environment is comprised of many different applications, e-mail, databases, e-commerce, and more. Each of these has its own threat profile and associated business risk. The complexity of the computing environment extends to the design of security solutions. Current methodologies for designing security systems include piecemeal designs and patchwork systems comprised of multiple point solutions. As the complexity of the business driven systems increase, these methods are being strained to keep up with security requirements. Systems science provides information on how complex systems interact with their environment, and this guidance can be applied to designing security architectures. Analysis and design of security systems using systems theory provides a new path to reduce the complexity.